Signal device for telephone systems.



A. E. CASE.

SIGNAL DEVICE FOR TELEPHONE SYSTEMS.

APPLICATION FILED JAN. 10. 1913.

Patented Jan. 30, 1917.

2 SHEETS'SHEET I.

A. E. CASE.

SIGNAL DEVICE FOR TELEPHONE SYSTEMS.

APPLICATiON FILED JAN. 10, 1913.

an. 30, 1917. 2 SHEETS-SHEET 2.

J d 8 t n m a D ARTHUR E.

CASE, @T GHTCAGO,

TLTJTNUTS.

SIGNAL DEVICE FUR TELEPHUNE SYSTEMS.

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Application filed January 10, 1913.

tion.

The invention relates to signaling devices for telephone systems.

is now common practice to transmit audible signals by connecting the signaling devices to the line so that the vibrations of the signaling device will be transmitted over the line to indicate some operation at the sub-station,-such as the deposit of a coin or token, or the operation of a register. Such devices necessarily involve a rigid connection between the signaling device and the transmitter of a telephone-set at the substation. ln may instances, the signaling-device cannot be conveniently mounted in lined relation with the transmitter, for example,

Where the transmitter is portable. Another objection to a resonant connection is the possibility of producing a counterfeit signal by mechanical vibration oil the signalingdevice.

The present invention designs to provide an improved signaling device tor telephonesystems Which is electrically and not necessarily mechanically connected to a telephone line, so that the signaling device may be fixedly mounted on a Waller elsewhere and transmit audible signals through a portable telephone-set or transmitter. This result is attained by causing the mechanical signaling device, to operate the armature of an electro-magnet by which the magnetic ilua through a helir; will cause variation of potential in the line of the same frequency as the mechanical vibration. This operation causes the-mechanical vibrations to be distinctly reproduced at the operators set at the exchange.

The invention also designs to normally short-circuit the electrical connections of the signaling-device from the line, and to cut out the telephone-set from the line during the operation of the signaling device. idesultantly, the device cannot be operated by the mechanical vibrations alone, and, therefore, it is exceedingly difficult to counterfeit the signal.

The invention consists in the several novel features hereinafter set forth and more par- Specificaticu of Letters Patent.

Patented Jan. 369, llttll't'.

Serial; no. tamer.

ticularly defined by claims at the conclusion hereot.

Tn the drawings: Figure l is a side elevation, parts being shown in section of a toll -apparatus embodying the invention. Fig. 2 is a section taken on line 2-2 of Fig. 3. Fig. 8 is a plan, parts being shown in section, of the toll apparatus embodying the invention. Fig. 4 is a diagram of the electrical connections atthe sub-station, it being understood that the usual circuits and connections are provided at the exchange. Fig. 5 is a detail View of the electromagnet and its armature.

The mechanical signaling-device, exemplitying one for producing audible signal comprises a Wire gong which has one of its ends lined as at ll to a support or frame 12. The coiled portion of the gong is free to vibrate, as usual in devices for producing an audible-signal of this character. A hammer 13 Which is pivoted as at it and is op erataad in one direction by a spring 15 is adapted to strike and vibrate the vvire-gong to produce an audible signal. Spring 15 operates the tail 16 of hammer 13 against a stop ll Which causes the hammerto be held normally out of contact with the Wire-gong and to rebound from the gong after it strikes it. This hammer serves to vibrate the signaling device mechanically and any suitable means may be employed to operate the haminer.

'The invention utilizes the mechanical vibration ot the audible signaling device to operate an armature 2i which is lined to a vibratory portion of the gong, so that the vibration oi the gong Will cause vibration oil the armature. This armature vibrates to and from the pole-pieces 22 of a permanent magnet 23 Which is secured by screws 24; to a block 25 on support 12. Resultantly, mechanical vibration of armature 21 which is in the field of permanent magnet 23 causes field changes in the magnetic this: through helices 27 which are Wound on the pole pieces 22 and are included in a conductor 28 which is bridged across two conductors through Which currents pass from the exchange in the usual manner. When the current cannot flow over the line except through conductor 28, currents of the same frequency of the mechanical vibrations will be caused to flow over the line as a result of the mechani cal vibration of armature a which causes the magnetic field to vary and to correspondingly change the magnetic flux through the coils of wire. The circuit over which these currents pass includes the exchange operators telephone-set and when the armature is mechanically vibrated, current of the same frequency as the mechanical vibrations will flow over the line to the exchange, transforming the mechanical vibrations into corresponding electrical currents, so that even the faintest tones will be transmitted over the line to the exchange-operator.

In the diagram of the substation equipment a and 6 denote the line-conductors, the latter of which is connected to a spring-contact 0 which normally engages a contact d. The latter contact is connected to a conductor e which terminates at the normally open switch-hook contact f. Line conductor a is connected to a conductor 9 which is connected to the switch-hook h. The transmitter i and receiver 70 are connected, as usual to the line, as well understood in the art. A contact l is disposed to be engaged by the contact 03 when the latter is moved away from the contact 0, and is connected by a branch-conductor m to the line-conductor a.

It is desirable that the transmitter at the sub-station shouldbe shunted out of the circuit during the operation of the signaling device, so that noises and side tones, other than those produced by the signaling-device will not be heard by the exchange-operator. For this purpose, when hammer 13 is operated at the sub-station by a coin, contact 01 will be operated away from contact 0 and into engagement with contact Z to shunt the transmitter of the sub-station set from the line and also to put helices 27 in. the circuit between the exchange and the sub-station, so

that electric currents of the same frequency as the mechanical vibrations produced by the signaling device will be transmitted over the line to the exchange.

In operation contacts a and d are normally closed, and when the receiver is off the switch-hook, the sub-station set will be connected to the line for speech-transmission, as well understood in the art. When the signaling-device is operated, contact d will be simultaneously operated to shunt the telephone set from the line and to include the helices 27 in the circuit by mechanism hereinafter described. Assuming, the line-conductors to be connected to a source of potential at the exchange and the exchange-operator to be connected with the line as usual, current will flow over a circuit including the following: line-conductor a, conductor m, contacts Z, d, conductors e, 28 in which the helices 27 are included and line-conductor b. The mechanical, vibration of armature 21 resulting from the "operation of the gong by hammer 13, in the magnetic field will vary.

the magnetic flux through the helices and vary the potential flowing over the line.

Currents of the same frequency as the mechanical vibrations will result and the mechanical vibrations will be transformed into electrical impulses which will be reproduced and heard at the exchange.

The improved signaling device is exemplified in connection with coin-controlled mechanism for operating it. This mechanism comprises a coin-carrier orhopper 33 which is rigidly secured to a shaft 34 which is journaled in the frame 12 in suitable manner. A coin deposited through a slot 35 in the case 36 is directed by a guide 37 into the hopper wherein it will be held by a suitable coin-stop 38. A lever 39 is secured to the carrier-shaft 34 on the outside of the case and after deposit of the coin, the depositor will operate the lever 39 to manually shift the carrier to cause the coin to engage an arm 40 on a shaft 41 which is journaled in the frame, and after operating said arm, the coin is discharged from the carrier by gravity. An arm 42 carries a pivoted springpressed pawl 43 which engages a tappetwheel 44 and operates said wheel in one direction, that is, during the retractile stroke of carrier 33. Arm 42 is rigid on the carriershaft 34 and a toothed dog 45 engages the outer end of arm 42 to secure it against rctraction until a full stroke has been imparted to lever 39. A spring 46 is connected to retract the carrier 33, shaft 34 and lever 39. Tappet-wheel 44 operates the tail 16 of hammer 13, so that spring 15 will cause the hammer to strike the gong. Dog 45 is pivoted at 45 and is normally pressed by a spring 47, into operative relation with arm 42. A stud 48 on said dog is engaged by a cam 49 which is rigid on the carrier-shaft to disengage dog 45 from arm 42. A detent 66 serves to hold the dog away from the arm during'the retraction of the arm, and at the end of each stroke of the arm will release the detent, so that the dog will be operative during the succeeding stroke of the arm. In operation, shaft 41 will be rocked by the coin and arm 42 will be simultaneously shifted. Dog 45 will secure arm 42 against retraction until lever 39 operates cam 49 to engage stud 48, which releases the arm and causes the dog to be held by detent 66. hen the arm is thus released, spring 46 will retract carrier 33, shaft 34 and lever 39. A retractile spring (not shown) is applied to retract shaft 41 and arm 42 to cause pawl 43 to operate tappet-wheel 44 which will operate the hammer 13 to operate the wire gong to produce a mechanical signal, the desired number of strokes.

Switch-contact d is held normally against contact 0 by an arm which is pivoted on a pin 51. When arm 50 moves away from contact d, the latter will spring into engagement with member Z. A'device is provided for causing the contact'd to remain in con- (ill nails,

tact with contact Z during the operation of the mechanical signaling device, so that there will be a complete circuit for the electrical transmission of the signal during the vibration of said device. A stud 52 is secured to arm i2 and extends into the slotted end of an arm 53 which is pivoted on pin 51 and is connected to a pneumatic cushion which comprises a cylinder 54E which is pivoted as at 55 and a piston 56 on a stem 57 which is pivoted as at 58 to arm 53. This cushion retards the retraction of arm .22 and the oper ation of wheel ll by the spring which is applied to retract shaft ll and its connected parts including arm 42, so that the wheel will operate slowly and cause definite periods to elapse between the strokes oil arm 13. Arm 58 is provided With an abutment 61 which normally holds arm 50 in position to cause contact 05 to engage contact 0. During the operation of arm 42 and the signaling operation, arm 53 will be out of its normal position shown in Fig. 2 and contacts 0, at, will be separated and contacts 01 and 5 will be closed. After each signaling operation,

abutment hi on arm 53 will engage arm 50 to separate contacts 03 and Z and close contacts 0, d to restore the line to normal position.

The invention thus exemplifies a mechanical signaling device which need not be attached to the telephone-set at the sub-station and which will eliminate all other noises from the line during the operation of the signal. The helices of the signaling device are normally short-circuited, so they will not interfere with efi'ective speech transmis sion. The signals transmitted are loud, pure and distinct, and cannot be simulated.

The invention is not to be understood as restricted to the details set forth since these may be modified within the scope of the appended claims without departing from the spirit and scope or the invention.

Having thus described the invention, what i claim as new and desire to secure by Let ters Patent, is:

l. The combination with a telephone line, of a sub-station, including a transmitter, a mechanical vibratory signaling device sustained independently or the transmitter, means for electromagnetically transmitting the signal over the line, means for operat ing said device and means controlled by said operating means for shunting the telephone set from the line during the operation oisaid device by the operating means and for a predetermined period thereafter.

52., The combination with a telephone-line, of a sub-station including a transmitter, a resilient vibratory signaling device mounted independently of the transmitter, means for electro-magnetically transmitting a signal over the line, means .for operating said device, and means controlled by said operating means for shunting the telephone set ear from the line when said device is operated by said operating means and during the residual vibration oi the device.

3. The combination with a telephone-line, or a sub-station, including a transmitter, a mechanical vibratory signaling device mounted independently of the transmitter, means for electro-magnetically transmitting the signal over the line, means for operating said device, and means controlled by said operating means for shunting the telephone setrrom the line during the transmission of a signal.

i. The combination with a telephone line, or a sub-station including a telephone set, a mechanical signaling device, an electromagnet connected to the line, an armature for the magnet operated mechanically by said device, and operated mechanically by said device to vary the magnetic flux and the flow of potential over the line responsively to the mechanical vibrations of said device, and means for shunting the telephone set trom the line during the transmission of a signal.

5. The combination with a telephone line, oil a sub-station, a mechanical signaling device, electro-magnetic means connected to the line operated mechanically by said device for varying the magnetic flux and the flow of potential over the line according to the mechanical vibrations of said device, and means for conjointly causing the operation of said device and shunting the telephone set trom the line during the transmission of a signal,

6. The combination With a telephone-line, of a sub-station including a telephone set, a mechanical signaling-device, an electromagnet connected to the line, means operated mechanically by said device to vary the magnetic flux and the How of potential over the line according to the mechanical vibrations of said device, said magnet lacing bridged across the line, and a switch connected to shunt out the telephone set and to cause potential to flow through the magnet during the transmission of a signal.

'3". The combination with a telephone-line, of a sub-station including a telephone-set, a mechanical signaling device, an electromagnet connected to the line, means oper ated mechanically by said device to vary the magnetic flux and the flow of potential over the line according to the mechanical vibrations of said device, a switch for controlling the flow oi? potential through the magnet and connected to shunt the telephone-set from the line, and means for conointly operating the signaling device and said switch.

8 The combination with a telephone-line, of a sub-station including a telephoneset, a mechanical signaling-device, an electromagnet bridged across the line, means optill Mill

Hill

Hill

erated mechanically by said device for varying the magnetic flux to responsively vary the flow of potential over the line according to the mechanical. vibrations of said device, a switch for controlling the flow of potential through the magnet and connected to shunt the telephone-set from the line, means for conjointly operatin the signaling device and said switch and holding-means for said switch.

9. The combination with a telephone line, of a sub-station including a telephone set, a mechanical signaling device, means for electro-magnetically transmitting a signal over the line responsively to said device, means for shunting the telephone set from the line during the transmission of the signal andmeans for automatically rendering the telephone set operative When the signal has been transmitted.

10. The combination With a telephone line of a sub-station including a telephoneset, a mechanical signaling device, means including an electro-magnet for transmitting a signal over the line responsively to said device, a switch for shunting the telephone set from the line during the transmission of the signal and means for automatically rendering the telephone set operative when the signal has been transmitted.

11. The combination with a telephone line of a sub-station including a telephone set, a mechanical signaling device, means including an electro-magnet for transmitting a signal over the line responsively to said device, a switch for shunting the telephone-set from the line, means for holding the switch to shunt the set during the transmission of the signal, and means for automatically rendering the telephone set operative when the signal has been transmitted.

ARTHUR E. CASE.

Witnesses MILDRED STUMPF, FRANK S. BLANCHARD. 

